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Abstract:
Inferring astrophysical information from gravitational waves emitted by
compact binaries is one of the key science goals of gravitational-wave
astronomy. In order to reach the full scientific potential of
gravitational-wave experiments we require techniques to mitigate the cost of
Bayesian inference, especially as gravitational-wave signal models and analyses
become increasingly sophisticated and detailed. Reduced order models (ROMs) of
gravitational waveforms can significantly reduce the computational cost of
inference by removing redundant computations. In this paper we construct the
first reduced order models of gravitational-wave signals that include the
effects of spin-precession, inspiral, merger, and ringdown in compact object
binaries, and which are valid for component masses describing binary neutron
star, binary black hole and mixed binary systems. This work utilizes the
waveform model known as "IMRPhenomPv2". Our ROM enables the use of a fast
\textit{reduced order quadrature} (ROQ) integration rule which allows us to
approximate Bayesian probability density functions at a greatly reduced
computational cost. We find that the ROQ rule can be used to speed up inference
by factors as high as 300 without introducing systematic bias. This corresponds
to a reduction in computational time from around half a year to a half a day,
for the longest duration/lowest mass signals. The ROM and ROQ rule are
available with the main inference library of the LIGO Scientific Collaboration,
LALInference.